Submitted to: Journal of Clinical Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 3, 1999
Publication Date: N/A
Interpretive Summary: Malignant catarrhal fever (MCF), is a frequently fatal disease in cattle, bison, deer and certain other animals, caused by a group of herpesviruses. Until recently, only two pathogenic MCF viruses were identified: sheep-associated and wildebeest-associated MCF viruses. Using molecular approach, we identified a new herpesvirus causing MCF in white-tailed deer. MCF-like disease was diagnosed by clinical signs and lesions in 5 out of 6 white-tailed deer in a North American zoo. Sera from the deer had specific antibody to MCF viruses. Polymerase chain reaction (PCR) designed specifically for sheep- associated or wildebeest-associated MCF viruses failed to detect MCF viral DNA from these diseased deer. Using degenerate PCR for a region of a herpesviral DNA polymerase gene, a DNA fragment was amplified from all 6 deer and sequenced. Comparison of the sequences with other herpesviruses and MCF viruses demonstrated that the virus in the deer belongs to the herpesvirus family, exhibiting 81% identity to sheep-associated MCF virus and 72% identity to wildebeest-associated MCF virus. This new herpesvirus is the third reported pathogenic MCF virus, genetically distinct but closely related to the two previously reported MCF viruses. The reservoir for the virus has not been identified.
Technical Abstract: Malignant catarrhal fever (MCF) was diagnosed by clinical signs and lesions in 5 out of 6 white-tailed deer (Odocoileus virginianus) in a North American zoo. Clinical signs and histopathological lesions in these deer were typical of MCF. Antibody to an epitope conserved among the MCF viruses was detected in the sera collected from the deer. Polymerase chain reaction (PCR) failed to amplify viral sequences from DNA extracted from peripheral blood leukocytes (PBL) and/or spleens of the deer using primers specific for ovine herpevirus 2 (OHV-2) or specific for alcelaphine herpesvirus 1 (AHV- 1). Using consensus primers targeting a conserved region of a herpesviral DNA polymerase gene, a DNA fragment was amplified from the PBL or spleen of all 6 deer and sequenced. Alignment of the sequences demonstrated that the virus in the deer belongs to the Gammaherpesvirinae subfamily, exhibiting 81% homology with OHV-2, 72% with AHV-1, and 61% with a newly identified bovine lymphotropic herpesvirus. This virus, which causes classical MCF in white-tailed deer, is a new agent belonging to the MCF group of gammaherpesviruses. It is the third reported pathogenic MCF virus, genetically distinct but closely related to OHV-2 and AHV-1. The reservoir for the virus has not been identified.